Can be applied to any graphical program, really. Install it:
sudo apt install gamescope
Then use it like a wrapper for the app:
gamescope -w 1920 -h 1080 -f -F fsr -- <app_name>
This will provide a 1920x1080 display to the app and show it fullscreen (upscaled) on the actual display. -F fsr enables AMD GPU FSR upscaling, which I've had good experience using. Check gamescope --help for more options, and also note the hotkeys; e.g., fullscreen toggle with Super+F, nearest-neighbour filtering with Super+N, FSR filtering with Super+U.
You can also set this up to run Steam games by editing the game's launch options like so:
gamescope -w 1920 -h 1080 -f -F fsr -- %command%
(Note: Don't use the -e option to gamescope - that's meant for running steam itself inside, using the SteamOS interface.)